Hydraulic system



Oct. 31, 1939. R. s QUICK H N. 2,178.123

" HYDRAULIC SYSTEM Filed Oct. :50, 1935 8 Sheets-Sheet 1 INVENTORS Bag .5 Quick R.S. QUICK ET AL HYDRAULIC sYs'ml Filed Oct. 30, 1935 8 Sheets-Sheet 2 km we INVENTORS Pay 5. Quick George A. fiueh/e ATTORNEY.

Oct. 31, 1939. R. s. QUICK El AL HYDRAULIC SYSTEM Filed oci. 30, 19:55

8 Sheets-Sheet 3 1NVENTOR Bag 5. Qu/cl; 5e orge ,4 fiueh/e ATTORNEY.

Oct. 31, 1939.

R. s. QUICK ET AL HYDRAULIC SYSTEM Filed Oct. 30}. 1935 8 Sheets-Sheet 4 FIEJEL.

I INVENTORS Pay 5. Quick 'earge 4 .fiue/v/e Y ATTORNEY.

Patented Oct. 31, 1939" r nmaauuc srs'rm Roy 8. Quick, Burlingame, and George A. Buehlc,

San Francisco,

Calif-,- allllnors to The Pelton ,Water Wheel Company, San Francisco, Oaiifu a corporation of California -Application October so, 1935, Serial No. 47,480

15 Claims. 01. 131-139) This invention relates to means for controlling flow in hydraulic conduits and is particularly concerned with controlling means for conduits in which the flow must be regulated precisely. In some hydraulic conduits the characteristics of the fluid flow are of no particular concern and any alteration of the how is eflfected by relatively crude mechanism. In many hydraulic conduits, however, the characteristics of the flow (that is to say, its rate, its quantity, its rate of change, its head or pressure, and various other factors) are of considerable importance. The flow is regulated, usually, by some form of valve, and it is of great importance to guard against excessive pressure surges due to changes in position of the valve. It is also very desirable to be able to manipulate the valve precisely in order to control exactly the flow in the conduit. Furthermore, when the conduit includes other machinery, such as pumping mechanism for instance, the operation of the valve should be co-ordinated with the operation of the pump, so that under normal conditions the two will work in harmony and so that under abnormal conditions no deleterious effects or outright damage can occur.

Particularly where the hydraulic conduit includes a power-driven pump discharging" through a controlling valve into a pipe line, certain special factors should be taken into account. That is, if the electrically driven pump is started and discharges through an open valve into an empty pipe line, the electric motor may be overloaded and seriously damaged. If the pump is started against a closed discharge valve and the valve is opened quickly into a full pipe line, a severe pressure surge may occur which may be quite destructive to the hydraulic mechanism. Simi: larly, if, when the pump is operating, the discharge valve is closed quickly, a severe pressure surge may be set up. Further, if the electric power should fail when the'pump is pumping water through the line, the water in the discharge line tends to run backward through the pump, causing it to act as a turbine. The pump is usually so constructed that it runs faster as a turbine than as a pump, and overspeeding of the rotational equipment occurs, much to its detriment. Even so, the discharge valve must still be shut down in order to prevent exhaustion of the previously pumped water from the discharge system. If the discharge valve is closed without careful conrol, a severe surge is set up in the discharge line, which may damage the equipment and may even rupture the line.

It is therefore an object of the invention to provide a hydraulic conduit having avalve ther in, in which the operation of the valve is governed automatically.

A further object of the invention is to provide means for controlling a valve in such a way that no' deleterious surges occur in an associated hydraulic conduit and so that stresses arising out of operation of the valve will not exceed designed amounts.

An additional object of the invention is to provide a precisely operating valve, even of large size, which can readily be controlled by comparain connection with an electrically driven pump in such a way that no severe surges can occur due to the operation of the pump or of the discharge valve.

The foregoing and other objects are attained in the embodiment of the invention illustrated in the drawings, in which- Fig. 1 is a diagram showing in side elevation a hydraulic system in accordance with the invention, particularly illustrating a valve in installed environment, together with diagrammatic representation of some of the controlling structure.

Fig. 2 is a diagram partially in cross-section through the median plane of a valve, with part of the hydraulic circuit and controlling instrumentalities.

Fig-3 is a diagram showing the'valve actuating and controlling mechanism.

4 is a cross-section of a valve in accordance with the invention, the plane of section passing through the vertical axis of the valve.

Fig. 5 is a cross-section transversely ofthe valve on the line 5-5 of Fig. 4, showing part of the interior mechanism in end elevation.

Fig. 6 is a cross-section the planes of which are indicated by the lines.6-6 of Fig. 4.

Fig. '7 is an enlarged detail showing part of a position-responsive mechanism.

Fig. 8 is a cross-section of a modified form of valve in accordance with the invention, the plane of section passing through the vertical axis of the valve.

Fig. 9 is a, partial cross-section of the upper part of the valve of Fig. 8, the plane of section 86 being at right angles to the plane of section of Fi 8.

Fig. 10 is a side elevation of the upper part of the valve oi Fig. 8, showing a modified positionresponsive mechanism.

Fig. 11 is partially diagrammatic and shows in end elevation part of the controlling mechanism.

Fig. 12 is a front elevation of the mechanism shown in Fig. 11.

Fig. 13 is a view similar to Fig. 12 but showing to an enlarged scale details of the position-responsive controlling mechanism.

Fig. 14 is a partial cross-section transversely through the mechanism of Fig. 13.

Fig. 15 is a plan view of the controlling mechanism as shown in Fig. 13, some of the electric circuit being shown diagrammatically.

In its preferred iorm, the hydraulic system of our invention includes a hydraulic conduit in which flow is established by a power-driven pump and in which a valve is situated to control the flow, there being provided a servo mechanism for moving the valve under control of various instrumentalities both manual and dependent upon various factors, such as conduit pressure, power failure, and the like.

While the hydraulic system which is the subject-matter of the present invention can be modified materially in accordance with the particular environment in which it is installed, and while it can be altered considerably in mode of operation to fit especial installation circumstances, there is described herein typical mechanism which illustrates the general characteristics and mode of operation of the hydraulic system.

A source of liquid 8 is connected by a relatively large, relatively long hydraulic conduit 1 to a terminal reservoir! which is at an elevation above the inlet reservoir 8. Interposed in the pipe line 1 is a pump 0 driven by a suitable source of power, such as an electric motor III, for transferring the fluid from the reservoir 6 to the reservoir 8 through the pipe line. It is desirable that flow in the pipe line 1 be controlled with the utmost nicety in order to avoid stresses which are above those calculated in the design and in order that smooth functioning of the installation will be continued uninterruptedly. For this purpose a valve II is interposed in the pipeline adjacent the pump 9 but on the pump outlet pipe i2 or on the side .of the pump away from the intake reservoir 8. The valve I I, as particularly shown in Figs. 4 and 5, incorporates a central casing 13 which is a body enclosing a central chamber ll by means of walls It reinforced by integral ribs i1.- Intersecting the casing II is a conical through-passage [8, the larger or discharge portion i9 01' which is terminated by a fastening flange 2| intended to be secured to the hydraulic line pipe 22, while the smaller or inlet portion 23 is terminated by a fastening flange 24 for attachment to the outlet pipe i2 01 the pump 0.

Adapted to co-operate with the passageway i8 and to operate within the chamber I 4 is a valve body 21, in general occupying a large part of the space within the chamber l4 and in effect incorporating an upper portion 28 and a lower portion 29. The lower portion is a so-called "follower ring which, when the body 21 is translated into its upper or open position, will be interposed between the portions l8 and 23. Since the body 21 is provided with a conical bore 30, it affords a substantial continuation of the portions It and 23 so that there is no materia or significant interruption to hydraulic flow through the entire valve when the valve is in open position.

In the closed position of the valve, as illustrated in Fig. 4, the follower ring is disposed in the lower portion of the chamber ll which is extended by a closure cap ll bolted to the walls II. The ring 29 is protected by a pair of guard plates 82 which are situated both in the casing i3 and in the cap II to lie in close juxtaposition with the follower ring and to prevent entrance of debris into the cap. A drain hole ll in the cap, usually provided with a cock (not shown), permits flushing of the interior thereof whenever necessary.

' In the closed position of the valve the upper or gate portion 28 of the body 21 is disposed so that a pair of circular sealing rings 34 carried by the body are in close proximity to a similar pair oi sealing rings 38 disposed within the casing II. The pressure of water on the body 21 causes it to move sidewise slightly and to seat very tightly on whichever of the rings it happens to be on the low pressure side, so that no leakage through the valve occurs.

Since under normal operation it is desirable to operate the valve only when the inlet 23 and the outlet 19 contain water, there is preferably built into the casing l3 means for by-passing fluid around the valve body 21 even when it is in closed position. A by-pass inlet duct 31 extends from the inlet portion 23 exteriorly oi the body I3 to a regulator 38, and from the regulator a by-pass outlet 39 extends back into the outlet portion II. There is thus provided a path for fluid flow around the valve body 21 subject to the control of an instrumentality for that purpose. This mechanism (Fig. 2) preferably includes a valve chamber 4| having a valve seat 42 therein, against which a valve 43 can rest in closed position to preclude interflow between the duct 31 and the duct 39. The valve 43 is preferably moved by a piston 44 connected to the valve by a stem 40. A vent 1 permits the piston 44, and consequently the valve 43, to move freely in response to pres- "sure existing within a chamber 48 which is connected by a duct 49 to a conduit Ii. Thus the pressure conditions obtaining in the ,conduit ii are eflective to control flow through the by-pass from one side of the valve body 21 to the other.

Pressure conditions in the conduit 5| are made dependent upon pressure conditions adjacent the inlet portion 23 and the outlet portion l9. Thus, the pressure existing in the portion 23 is transmitted by a pipe 52 to an expansible chamber 53, one wall of which is movable, for instance being in the form of a piston 54. The piston 54 is on a stem 56 which also carries a valve 51, while a spring 58 urges the valve toward closed position. A conduit 59 around the stem 56 permits flow therethrough to a discharge pipe 6i.

The fluid controlled by the valve 51 is derived preferably from the outlet I!) through a pipe '2 joined to the conduit 51 through a metering oriflce 63 the area of which is less than the discharge area of the pipe 61, so that when the valve 51 is opened the pipe 61 can dispose of the fluid content of the conduit 5i and permit the piston ll to move into such a position that the valve is unseated and by-pass flow 01 fluid takes place around the body 21. On the other hand, when the valve 51 is seated, due to absence of pressure in the inlet portion 23, the orifice 63 passes suflicient fluid from the pipe 22 so that the piston 44 seats the valve 43 and no flow takes place through the by-pass ducts 31 and 39.

For intermediate ressure conditions in the inlet portion .23, the pipe 82 transfers intermediate pressures to the piston 38 so that the valve 31 likewise occupies an intermediate position. If fiow through the oriflce 83 is exactly equalled by outflow past the valve 31 and through the pipe 8 I, the parts will remain in equilibrium; whereas if flow through the oriflce'83 exceeds the possibility of discharge past the valve 11, the piston 44 will close the valve 43. On the other hand, if flow through the orifice 83, is less than can pass the valve 31, the valve 83 is opened to permit bypassing.- Since the valve 31, which controls the discharge, is sublectto the pressure in the inlet portion 23, and since the orifice depends for the quantity it will pass upon the pressure within the discharge portion II, the by-pass ducts 31 and 39 are affectedby the relationship of the pressures within the portions I9 and 23, and these values can, by the design of the apparatus, be fixed at any amount desired. The by-passingmechanism therefore operates automatically in such a way that conditions on both sides of the body 21 are as nearly as possible maintained ina predetermined relationship.

In accordance with the invention a servo mechanism (that is, a mechanism which uses controlled auxiliary power for eifecting the desired movements) is provided for moving the body 21. It is desirable to save as much space and as much machinery as possible, and consequently the body 21 itself is utilized as part of the servo mechanism. The interior of the body is preferably formed to provide a circular cylinder 19 which is lined with" a suitable deterioration-resistant liner H. The lower end of the cylinder 18 is closed by the bottom of the body 21 itself, whereas the upper end is sealed by a detachable cap 12 secured in place to form a fluid-tight enclosure. Disposed within the cylinder is a piston 13 mounted at the end of a pistontube 14 passing through a suitable stufling gland 13 on the cap 12. The tube 16 traverses a chamber 11 defined by a closure hood 18 secured to the walls I6, and the tube 18 is anchored inthe hood 18 by a removable fastening 19.

The piston 13 divides the cylinder 19 into an upper chamber 8| and a lower chamber 82, the relative volume of the chambers being proportional to and indicative of the position of the follower ring 29. That is, when the chamber 82 is -of maximum volume, as shown in Fig. 4, the body 21 is in the position therein shown, the. follower ring.29 is in its lower position, and the valve is closed. on the other hand, when the volume of the chamber 82 is a minimum and that of the chamber BI is a maximum, then the follower ring 29 and the body 21 are in the "upper position indicated by dotted lines in Fig. 4. The valve is then open, since the follower ring 29 is in registry with the portions I9 and 23. Intermediate volumes of the chambers 8i and 32 provide for corresponding intermediate positions of the valve.

A means is provided for varying the relative volume of chambers 8| and 82 in order to control piston tube 18 and emerges from a fitting 88 at' the top of the hood 18. Similarly, communication from the chamber 8| is by means of radial 83 and the pipe 99 into th slots 88 into radial holes 81 in a sleeve 88 within the piston tube 18, the sleeve 88 terminating in the interior of a cup 8! access to which is had through a pasage 9|. Working fluid for the servo mechanism is derived from a reservoir 92 and is 5 put under pressure by a suitably operated pump 93 discharging into a pressure line 94 and with which an accumulator Ills connected to maintain a large body of oil under pressure. From the accumulator the oil pressure line 94 extends 1 to a servo valve casing 98 wherein it intersects a centrally a circular cylinder 91. Likewise intersectingthe cylinder 91 is a pipe 98 from the passage 9| and a pipe 99 from the fitting 84. Additionally, a drain tube IIII and a drain tube 5 I82 lead from the servo cylinder 91 back to the oil reservoir 92.

Adapted to operate within the cylinder 91 is a servo piston I83, including an upper land I04 and a lower land I83 separated by a spindle I91 20 which extends above the cylinder 91 and is guided in a stationary bracket I88. When the servo piston I93 is in an intermediate or neutral position, as shown in Fig. 2, the pipes 98 and 99 are blocked and no hydraulic flow occurs. When the g5 piston I83 is lowered to closing" position, the land I83 uncovers the pipe 99 to admit pressure liquid from the pressure line 98,.and simultaneously the land I94 uncovers the pipe 98 for flow to the drain III. The pressure fluid then flows so through the line 94 into the pipe 99,, through the inner tube 83, and into the lower chamber 82,

,while the upper chamber 8| simultaneously discharges through the tube 14 and the pipe 98 into is thus moved downwardly toward its lower or closed position.

Conversely, when the servo piston I03 is lifted to opening position, the land Ill uncovers the pipe 98 to pressure from the line 98, and simul- 4|) taneously the land IIIG uncovers the pipe 99 to drain I92. Under this circumstance, pressure fluid enters through the lead 94, passes into the pipe 98 down through the outer tube 14 into the chamber 8|, and tends to enlarge the upper 45 chamber. Simultaneously, the chamber 82 contracts, discharging fluid through the central tube in I82. The valve body 21 is consequently .uved toward upper or open position.

In accordance with th" invention, means is provided for automatically effecting suitable positions of the servo piston I93 in order to control the operation of the main valve. For this purpose there is provided a means responsive to the 55 position of the valve body 21, located outside of the valve casing I3. Since the range of movement of the valve 21 is relatively large, but since a long range of movement is not necessary for the responsive mechanism, it is arranged that w the movement of the responsive mechanism be proportional to the movement of the main valve.

One mechanism for this purpose is shown in Figs. 5, 6 and '7 especially, and includes the provision on the valve body 21 of an inclined plane 65 I26 against which a cam follower I21 operates. The follower passes through a bushing I29 in the walls I9, and a packing I3I precludes material leakage. The follower I21 is connected by a link I32 to one arm I33 of a bell crank fastened on a 10 shaft I34 journaled in a-pedestal I35 secured to the walls IS. A pendant weight I36, connected to an arm I31 of the bell crank, tends to hold the follower I21 in close contact with the plane I26.

Thus, as the valve body 21 rises and falls its rela- 75 tive position is followed by the shaft I34. This movement is transmitted by a lever I88 fastened on the shaft I34 and a link I39 pivoted thereto, to an arm I (Fig. 12) of a bell crank which is pivoted on a pin I42 carried by abracket I48 conveniently clamped between flanges I44 on the pipe 98. The other arm I46 of the bell crank is connected by a link I41 to a rectilinearly translatable slide I48.

The slide I48 is conveniently disposed on the servo valve casing 96 and includes a plate I8I pierced by a longitudinal slot I52. Rollers I53 (Fig. 14) operate in the slot I52 and are carried on pins I54 engaging an upturned flange I66 on the casing 96 and likewise engaging a guide angle I51 on the body 96. The angle I51, together with the flange I56, forms a guide for the plate I55. The movement of the slide is directly in accordance with the movement of the main valve body 21, so that as the valve body rises from its closed position toward its open position, the slide I48 moves from left to right (Fig. 12) and, reversely, as the valve body lowers from its open position I toward closed position, the slide I48 moves from right to left.

While the position of the slide I48 aflords a visual indication of the proportionate position of the valve body 21, a direct visual indication is preferably provided .by a rod I6! (Fig. 5) secured to the cap 12 and extending through the hood 18 to the exterior. A packing gland I62 precludes leakage, while a pointer I83 serves as a datum point.

In order that the valve casing need be pierced at but one point, to provide an emergency mechanical means for moving the valve body 21 and for'other purposes, the construction illustrated in Figs. 8, 9 and 1.0 is adopted. In this arrangement the piston tube 14 is somewhat enlarged in diameter, as is the concentric tube 83. The tube 14 connects through the passage 9i with the pipe 98, while the tube 83 connects through the cup 89 and a passage I66 with the pipe 89. The hydraulic operation of the valve body 21 is the same as has been described. In the present modiflcation, the body 21 is provided with a central boss I61 to which a central lifting rod I68 is attached. The rod I68 passes through a stufllng gland I69 in the cup 89 and terminates in a lifting ring I1I.

If for any reason it is desired to move the valve body 21 without using the hydraulic mechanism provided for that purpose, the lifting ring I1I can be engaged by any suitable mechanism and, by reason of its connection through the rod I68 to the valve body 21, can eflect movement of the valve body. Since the rod I68 partakes of the movement of the body 21 it is provided with a pointer I12 traversing a scale I13 mounted on the hood 18 to give a direct visual indication of the valve position.

The pointer I12 also serves to transmit the valve movement to a linkage for moving the slide I48. A cable I14 is fastened to the end of the pointer and'extends around a large pulley I16 fastened on a shaft I11 journaled in brackets I18 and I19 on the hood 18. So that the range of movement to be transmitted will not be so great, a small pulley I8I is fastened to the shaft I11 and carries a cable I82. A pulley I83 journaled in a bracket I84 on the hood 18 turns the cable I82 which is then passed around a sheave I86 at the end of the plate I5I and is anchored to the bracket I84. To effect return movement of the slide I48 and to maintain the cables taut,

I a strong spring in is fastened to the plate III and to an arm I88 on the bracket I19. with this arrangement the slide I48 is moved to the right and to the left in accordance with the lifting and lowering movement of the valve body 21.

The movement of the slide I 48 is utilized to limit the amount of opening of the valve body- 21 by stopping the valve body in any selected location. To this end the plate I H carries in suitable journals III a screw shaft I9I which at one end carries a gear I92 meshing with a gear I93 driven by a reversible electric motor I94 mounted on the plate I 8|. Power to the motor is carried through flexible conductors so that movement of the motor with the slide does not affect the supply of power. By suitable controls the operator can energize the motor I94 so that through the gears I92 and I92 the screw shaft I9I is rotated in either direction. This rotary movement of the screw shaft translates an opening limit wedge I96. This wedge is an internally threaded cam rectangular in transverse crosssection to translate without rotation on the plate I 6| and is provided with an inclined face I91.

The slide I48 moves toward the right (in Figs. 12 and 13) as the valve 21 opens, until such time as the limit wedge I96 is moved against and translates a plunger I98 (Fig. 14) mounted for reciprocation in the bracket I88 on the servo valve casing 96. Movement of the plunger I98 is made eflective through a coil spring "I on a plunger rod 282 which abuts one lever 283 of a bell crank pivoted about a pin 284 on a bracket 286 secured to the casing 96. The bell crank likewise incorporates a counterweight 281 so that the lever 283 normally urges the rod 282 towards the left (Fig. 14) so that a stop collar 288 contacts with the bracket I88. A coil spring 289 normally urges the plunger I98 into the path of or into abutment with the opening limit wedge I98. Also incorporated with the bell crank is an arm 2 which at its terminus bears against a collar 2I2 on the servo piston spindle I81. If a superior force urges the spindle I81 upwardly so that the collar 2I2 rotates the bell crank about the pin 284 in a counter-clockwise direction, the rod 282 compresses the coil spring 28I which yields under this force. Normally, however, the opening limit wedge I98 is effective through the coil spring "I to rotate the bell crank about the pin 284 so that the collar 2I2 is forced downw dly. The wedge I96 restores the servo piston I82 to neutral position, thereby stopping the valve body 21 in an intermediate location dependent upon the relative location of the wedge I96 on the slide I48. The wedge face I 91 is of sufficient extent to move the spindle I81 from open position through neutral position into closing position, but when the wedge I96 is moved by the slide I48 alone it is ineffective to do more than move the spindle I81 to neutral position, since when the servo fluid is cut oil the valve body 21 stops and, correspondingly, the slide I48 stops also.

Since the operator by controlling the motor I 94 governs the position of the wedge I96 and consequently the open position of the valve, means is provided for precluding over-travel of the wedge. This is eilected by controlling the electric circuits of the motor I94. A power supply conductor 2I6 (Fig, 15) extends to a knife switch 2" which can be moved from a central "oi!" position into abutment with a contact 2I8 or with a contact 2I9. From the contact 2I8 a conductor 22I extends through a flexible lead 222 to a switch 228 (Fig. 13) mounted on the slide a the motor I34 moves the wedge I36 arran e I43. The switch isnormally closed by a springpressed plunger 224 spanning contacts 226 at the end of the lead HI and at the end of a conduc tor 221. But when the wedge I33 is in its fully open position near the end of the threads on the screw shaft I3I, it displaces a finger 223 on the plunger 224 and opens the switch. The con-- is opened automatically by the wedge I36 and the motor I34 is de-enargized.

From the contact 2I3 a conductor 233 extends through a fiexible'lead 234 to a switch 236 (Fig. 14) identical with the switch 223and having a finger 231 moved by the plunger I33. The switch 236 is normally closed, but when the plunger is fully translated by the wedge I36, the switch,

236 is opened. A conductor 233 extends from the switch 236 to the reverse field winding 233 of the motor I34 from whence the circuit is completed through the lead 231 and the conductor 232.

By closing the switch M1 on the contact 2I3 the operator energizes the winding 233 so that the motor I34 moves the wedge I36 toward the right (Fig. 15). This movement can be stopped in any position by opening the switch 2I1, but if the switch is left closed the wedge I36 continues its movement until it abuts and translates the plunger I33. This translation causes the finger 231 to open the switch 236, and the motor I34. is automatically de-energized.

in order that the valve body 21 will move precisely at the correct rate during itsfinal closing movement, so as not to produce deleterious surges or stresses during movement through this critical range, there is provided on the slide I43 a closing limit cam mechanism. This mechanism includes a bar 24I (Figs. 13 and 1,4) which at its opposite ends is provided with yokes 242, the threaded stems 243 of which pass through threaded spools 244 provided with thumb knobs 243 and loosely journaled in brackets 241 secured to the plate I6I. By suitably rotating the thumb knobs 246, the opposite ends of the closing bar 24I can be suitably adjusted, either by inclining the bar from the horizontal or by vertically moving the bar parallel to itself. The bar is provided with a lower cam'face, having an initial closing portion 243, a transition closing portion 243, and a final closing portion 26l, the transition portion 243 having any contour which is indicated by the conditions of installation of the valve.

When the servo piston I33 is depressed into closed position and the valve body 21 responds thereto by descending toward valve-closed position, the plate I6I carries the bar 24I toward the left (Fig. 13) until the transition portion 243 rides upon an arm 262 of a bell crank which is pivoted on a pin 263 on the bracket I33. The

arm 262 is consequently depressed or rotated counter-clockwise (Fig. 14) so that another arm 264 of the bell crank is effective through a link 266 to rotate an arm 261 about a pivot axle 263. Mounted on the axle 263 is a pair of cams 263 which, being rotated, contact a collar "I and lift the spindle I61. The contour of thecams I 263 is effective through the full range of cam movement to lift the servo piston I33 from closed position almost but not quite up to "neutral" position. This movement takes place in accordance with the shape of the transition closing portion 243. As the valve body 21 returns more nearly to its closed position the contours of the transition cam 243' and the final closing portion 26I cause any desired graduation of closing movement by precisely controlling the servo piston I33. The cams 263 ensure an appropriate closing movement of the main valve body 21 but, sinwthey restore the piston I33 not quite to neutral position, the valve body 21 is moved into and held in closed position under pressure.

In addition to the means for limiting the valve to a selected open position, and in addition to the means for governing exactly the final closing I movement of the valve, there is preferably provided mechanism for establishing the normal rate of movement of the valve, so that the maximum speed of valve movement under all conditions cannot exceed a predetermined, adjustedrate. The spindle I31 of the servo piston I33 passes freely through a stop collar 266, formed as partof the bracket I33, and adjacent the collar 266 the spindle is threaded. Engaging the threads above the collar is a closing rate nut 261 and a locking or Jam nut 263. When the spindle piston. The nut 261 can occupy such a position on the threaded stem that the lands I34 and I36 will uncover fully their respective ports. A maximum hydraulic flow can occur through the servo mechanism and the valve body 21 moves toward closed position at the maximum designed rate. If the nut 231 is adjusted to permit only partial uncovering of the associated ports by the lands I34 and I36, 9. throttling of the servo liquid occurs and the valve body 21 movestoward closed position at less than its maximum rate. Similarly, mounted on the spindle is an opening rate nut 263 and a Jam nut 2" which limit the permissible rising movement of the spindle I31 and, depending upon their adjustment, either permit a full flow of servo liquid to open the-valve body 21 at its'maximum designed rate or stop the servo piston I33 in a position to throttle the opening'flow' ofservo liquid to effect a rate of valve opening which is less than maximum.

Additional factors are made effective upon the servo piston I33 and preferably are arranged in such a way that the driving power for the pump 3 is included in the-control. The electric motor I3 is preferably supplied with power by electric leads 26I and 262 (Fig. 1), the current being controlled by the two blades 233 and 234 of a master switch 266. A third blade 236 can be operated manually but is automatically opened in conjunction with the blades 233 and 234 by-a ceeds a predetermined amount, as established by a spring 29I, a switch 292 bridges the gap in the rent flows to the blade 286 through a conductor 291. From the switch 286 a conductor 298leads to a solenoid 299, and from thence a conductor 30I leads back to the main circuit, particularly to the conductor 28L When the pressure on either side of the main valve II is not suitable and the switches 289 and 293 are not closed, or when the master switch 285 is opened, or when the blade 286 is individually opened, the solenoid 299 is de-energized. The

solenoid 299 is preferably mounted on the casing 96, so that the solenoid core is effective upon a bell crank lever 302 pivoted on a pin 303 on the casing 96 and having an arm 304 bearing against the collar 2I2 on the servo piston spindle I01. Whenever the solenoid 299 is not energized, a multiple leaf spring 306 bears against a stub lever 301 to urge the bell crank lever to rotate about the pivot pin 303 in a clockwise direction, as seen in Fig. 12, so that the arm 304 urges the collar 2I2 in a downward direction, thus moving the servo spindle I01 and, correspondingly, the

servo piston I03 downwardly into closed position.

The relationship of the various control instrumentalities is disclosed diagrammatically in Fig. 3 which shows the closing limit bar 2 and the opening limit wedge I96 partaking of a proportion of the movement of the main valve body 21, illustrated in a half-open position. The valve body 21 has been in fully open position, as indicated by the relative position of the wedge I96, but the solenoid 299 has been de-energized so that the spring 306 has rocked the bell crank lever 302 to depress the spindle I 01 and move the servo piston I03 into its lowermost position as fixed by the closing rate nut 261 which abuts the stop collar 266. This movement of the spindle has compressed an opening spring 308, has lowered the collar 2I2 from the arm 2, and has lowered the collar 26I into abutment with the cams 259. As the valve body 21 approaches its fully closed position, the cam surface 249 restores the spindle nearly to central or neutral position against the urgency of the leaf spring 306. The servo piston I03. interrupts the flow of servo liquid and the system comes to rest with the valve II fully closed. The switch 285 for the pump motor I0 is preferably automatically opened as the valve closes.

The foregoing rapid closure of the valve is primarily for emergency use and especially in the event of power failure. By suitable manual operation of the switch blade 2 I 1 to move the opening limit wedge I96 toward closed position, it is possible manually to regulate the closure of the valve at any desired rate, but of course not in excess of the maximum rates fixed by the automatic mechanism.

The valve is subsequently opened either by manually lifting a knob 309 and the spindle I01 against the urgency of the spring 306, or by energizing the solenoid 299 which rocks the bell crank lever 302 to render the leaf spring 306 ineflective and thus giving eifect to the spring 308 which then lifts the spindle I01. 'In either case, the spindle is lifted as far as the opening rate nut 269 will permit, and the servo piston I03 admits of servo fluid flow to lift the valve body 21. The valve moves toward open position at the adjusted rate until the opening limit wedge I96 rocks the arm 2 to depress the c0llar 2I2 and the spindle I01 to neutral position. Operation of the servo mechanism is therefore interrupted with the valve II open.

Manual supervision may likewise be extended over the valve opening movement by operating the switch blade manually to move the opening limit wedge toward valve-open position relatively slowly and at any desired opening rate less than the opening rate fixed by the automatic mechanism.

We claim:

1. A hydraulic system comprising a casing having an inlet and an outlet, a valve body movable within said casing and having one portion for establishing communication between said inlet and said outlet and another portion for blocking communication between said inlet and said outlet, a cylinder incorporated with said other portion of said valve body, a piston in said cylinder and secured to said casing, means exterior of said casing for supplying said cylinder with fluid, and means extending from the interior of said casing to the exterior thereof for controlling said supplying means.

2. A hydraulic system comprising a casing having an inlet and an outlet, a valve body movable within said casing and having one portion for establishing communication between said inlet and said outlet and another portion for blocking communication between said inlet and said outlet, a cylinder incorporated with said other portion of said valve body, a piston in said cylinder and secured to said casing, means for supplying said cylinder with fluid, and means responsive to the movement of said valve body for controlling said supplying means.

3. A hydraulic system comprising a valve casing subject interiorly to hydraulic pressure exerted by a contained liquid, a valve body including a ring portion and a gate portion entirely contained and movable within said casing to control hydraulic flow through said casing, means isolated from said hydraulic pressure moving in accordance with the movement of said valve body, and means responsive to said moving means and at least in part immersed in said liquid within said casing for moving said valve body.

4. A hydraulic system comprising a casing adapted to contain liquid and having an inlet and an outlet coaxially disposed, a body within said casing having a gate portion and a ring portion adapted alternately to be disposed coaxially with said inlet and said outlet, means immersed in the liquid within said 'casing for moving said body selectively to dispose said gate portion and said ring portion coaxially with said inlet and said outlet, and means outside said casing and responsive to the movement of said body for controlling the operation of said moving means.

5. A hydraulic system comprising a casing adapted to contain liquid and having an inlet and an outlet coaxially disposed, a body within said casing movable at right angles to said axis to control communication between said inlet and said outlet, means immersed in the liquid within said casing for moving said body at right angles to said axis, and means outside said casing and responsive to the movement of, said body for controlling the operation of said moving means.

6. A hydraulic system comprising a casing the interior of which is subject to hydraulic prescasing having a gate portion and a ring portion selectively disposable between said inlet and said outlet, a cylinder within said gate portion, a piston within said cylinder, a piston rod connecting said piston and said casing, and means outside said casing for supplying said cylinder with operating fluid.

ing an inlet and an outlet, abody within said casing having a gate portion and a ring portion selectively disposable between said inlet and said outlet, a cylinder within said gate portion, a piston within said cylinder, a piston rod con! nected to said piston and to said casing, and means including passages through said piston rod for conducting fluid to said cylinder on opposite sides of said piston.

9. A hydraulic system comprising a casing the interior 01 which is subject to hydraulic pressure and having an inlet and an outlet, a body within said casing and having a gate portion adapted to be interposed between and withdrawn from between said inlet and said outlet, a cylinder within said body, a piston within said cylinder, 9. piston rod connecting said casing and said piston, and

means including passages in said piston rod for .conducting fluid to said cylinder on opposite sides of said piston.

1 A hydraulic system comprising a casing having a fluid passage therethrough, a hollow body movable transversely into and out of said passage to control flow through said passage, a stationary piston dividing the interior of the body into two chambers, meanstor circulating fluid under pressure to and irom the chambers to cause movement of the body, said means including a piston tube carrying the piston and a concentric tube go within the piston tube dividing the piston tube opening into two passages, one passage communicating with one chamber and the other passage communicating with the other chamber, a lifting rod connected to the body and extending longigg tudinally through the concentric tube, a servo pis-' ton for controlling the flow through the passages, and an operative connection between the lifting rod and the servo piston. 11. A hydraulic system comprising a go having a fluid passage therethrough, a hollow body movable transversely into and out of the pasf sage to control flow therethroush. a stationary piston dividing the interior of the body into two chambers, means for passing fluid under pressure gs intoonechamberwhilodischargingitiromthe 8. A hydraulic system comprising a casing haveasing other chamber to cause operation of the body, a servo piston remote from the body for controlling said passing means, means for manually operating said servo piston, and an independent operative connection between said servo piston and said body whereby said servo piston is moved into closing position upon predetermined operation of said body.

i 12. A hydraulic system comprising a casing having a fluid passage therethrough, a hollow 10 body movabletransversely into and out of the passage to control flow therethrough, a stationary piston dividing the interior of the body into two chambers, means for passing fluid under pressure into one chamber while discharging it from the other chamber to cause operation of the body, a servo piston for controlling said pass; ing means, means for manually operating said servo piston, and an independent connection between said servo piston and said body whereby said servo piston is moved into closing position upon predetermined operation of saidbody.

13. A hydraulic system comprising a hydraulic conduit, projections extending from opposite sides of said conduit toiorm a transverse casing the interior of which is subject to hydraulic pressure, a gate portion within said casing and movable transversely of said conduit into and out of one of said projections, a ring portion within said casing and movable transversely of said conduit into and out oi the other of said projections, said gate portion and said ring portion being comprised in a valve body, a hydraulic cylinder within said ,valve body, a piston within said cylinder, a piston ro'd connected to said piston and'to said casing, means including passages in said piston rod for conducting liquid to and from said cylinder on bothsides of said piston, and means outside said casing and moving in accordance with the movement of said valve body for controlling said con- 'ducting means. 14. A hydraulic system comprising a casing adapted to contain liquid and having an inlet and an outlet, a valve body movable within said casing for alternatively positioning a ring. to establish communication between said inlet and said outlet or positioning a gate toblock communication between said inlet and said outlet,

' means positioned in be immersed in said liquid within said casing -i'or eflecting movement of said valvebody, and means exterior of said .casing sensitive to movement of said valve body for controlling-said efl'ecting means.

iii. Ahydraulic system comprising a main valve adapted to move between an open position and a closed position, a servo mechanism for movin said main valve, means including a piston valve for controlling said servo mechanism, a member moving in accordance with the movement of said main valve, and a lost motion connection between said member and said controlling piston valve permitting motion of one without exerting force RAY 8. QUICK. GEORGE A. 

